... we have survived this far into the nuclear era only because we have been unaccountably lucky. Robert McNamara, I think, summed it up best. He said, “We lucked out. It was luck that prevented nuclear war.” It’s not because we had wise leaders or sound policies or infallible technology. And the current policy of the United States, of Russia, of China — of each of the countries which possesses a nuclear arsenal — is essentially a hope for continued good luck. And that’s an insane basis for policy. We can’t assume our luck is going to last forever. Sooner or later, if these weapons are allowed to exist, they’re going to get used. And if they are used, the consequence is going to be absolutely catastrophic.... we have always been shocked by the degree of ignorance on the part of world leaders about the potential damage that would be caused by their own nuclear arsenals. It’s part of the job, I think, of citizens in general, the physicians’ movement in particular, to educate leaders and the general public about this danger. No rational person who understood what nuclear weapons could do if they are used would countenance the continued existence of these nuclear arsenals. And that’s why we’ve seen so many of the people who were architects of the nuclear arsenals, of the whole nuclear strategy, who later in life turn into impassioned critics of this whole way of dealing with security.Ukraine operates four nuclear power plants with a total of 15 nuclear reactors, one of them the largest nuclear power plant in Europe, located 120 miles from the Donbas region, where the separatists and the Ukrainian forces have been fighting for years. Ukraine and the region could face another Chernobyl, or worse, if one of these plants was bombed or went offline due to a power outage, a fire, or if workers fled due to a threat of violence. I want to turn to a recent presentation made by Linda Pentz Gunter of the group Beyond Nuclear.Ukraine’s 15 reactors are all much older than Chernobyl Unit 4 was in 1986. They have bigger radioactive inventories, and they are all multiple reactor sites. People all across Europe would be affected.... there are 93 nuclear reactors, I believe it is, in the United States today, many across the rest of Europe. And each of these reactors is essentially a prepositioned weapon a mass destruction that we create and build and make available to potential enemies to detonate on our own territory.As few as 250 relatively small nuclear weapons, less than a half of a percent of the world’s nuclear arsenals, can cause enough climate disruption to tank agricultural production across the planet and trigger a global famine that we have estimated could put up to 2 billion people at risk of starvation.A war between the United States and Russia would be a worldwide climate disaster. Hundreds of millions — perhaps as much as 150 million tons of soot would be put into the upper atmosphere, blocking out the sun, dropping temperatures across the planet an average of 18 degrees Fahrenheit. In the interior regions of North America and Eurasia, temperatures would drop 45 to 50 degrees Fahrenheit. We haven’t seen temperatures on this planet that cold since the last ice age. And under these conditions, the ecosystems which have evolved in the last 10,000 years would collapse, food production would stop, and the vast majority of the human race would starve to death. This is what we’re facing. And this is the danger we’re going to be facing as long as we allow nuclear weapons to exist.